My exposure to Mistral is from a user/deployer perspective given that TripleO used Mistral on the undercloud up through train. TripleO itself does not have any usage of yaql's format function, with either Mistral or Heat templates.
That being said, Mistral does allow users to upload any YAML that may contain yaql, including usage of format. Given that, it will need a similar fix as Heat/Murano, and other services that may allow a similar behavior.
My exposure to Mistral is from a user/deployer perspective given that TripleO used Mistral on the undercloud up through train. TripleO itself does not have any usage of yaql's format function, with either Mistral or Heat templates.
That being said, Mistral does allow users to upload any YAML that may contain yaql, including usage of format. Given that, it will need a similar fix as Heat/Murano, and other services that may allow a similar behavior.